The burden is then placed upon the government to deal with those who have been radicalised as a result, Wallace said in an interview with The Sunday Times.

“Because content is not taken down as quickly as they could do, we’re having to de-radicalise people who have been radicalised,” he said. “That’s costing millions.”

‘Ruthless profiteers’

He said problems were being caused by content distributed by internet platforms such as Facebook and Google-owned YouTube, as well as messaging services such as Facebook-owned WhatsApp, whose messages are encrypted and as such not readable by government investigators, meaning more must be spent on surveillance.

Such services were “turning the internet into an anarchic, violent space”, Wallace said.

“Because of encryption and because of radicalisation, the cost of that is heaped on law enforcement agencies,” he told the paper.

“We should stop pretending that because they sit on beanbags in T-shirts they are not ruthless profiteers,” Wallace said. “They will ruthlessly sell our details to loans and soft-porn companies but not give it to our democratically elected government.”

He said if companies continued to be “less than co-operative” the government should “look at things like tax as a way of incentivising them or compensating for their inaction”.

Wallace’s quoted comments didn’t give further details, but the paper said any levy would take the form of a windfall tax similar to that imposed on privatised utilities by the former Labour government in 1997.

Investment

Facebook said the minister was “wrong” to say the company put profits before safety.

“We’ve invested millions of pounds in people and technology to identify and remove terrorist content,” said Facebook executive Simon Milner in a statement.

The company said it removed most extremist content within one hour of its being discovered and sait it planned to double the number of people working in its safety and security teams to 20,000 by the end of 2018.

It said most militant content was removed automatically, before being reported by users.

The UK was hit by a series of militant attacks between March and June of this year, including a bombing at a concert in Manchester in May that killed 22 people.

Wallace’s remarks are the latest move by the government to put pressure on IT firms over the problem, but some experts have said it is simplistic to put the blame on internet companies for a complex issue.